1. Field of the Invention
The present invention relates generally to the field of user interfaces for portable electronic devices, as well as to the field of wireless myoelectric control.
2. Description of the Related Art
Portable electronic devices have become increasingly popular. These devices can operate with the use of a small battery pack or battery cells. Examples of these devices include wireless or cellular telephones, personal digital assistants (PDAs), and audio or music delivery devices. Some devices have become increasingly small such that they are now deemed "pocketable" and/or "wearable."
A portable electronic device typically has a user interface for operative control. Most if not all conventional user interfaces for such portable electronic devices employ physical buttons, stylus, or voice control. In some devices, a large number of operations or functions are possible with the user interface.
One major shortcoming of a button or stylus-based user interface is that the user must physically retrieve and position the portable electronic device appropriately for physical contact therewith. In addition, as the size of a device becomes smaller, the interface becomes increasingly inappropriate from an ergonomic standpoint. The major shortcoming of a voice-controlled interface is that the user must speak openly in such a way that other nearby people may hear.
Myoelectric technologies are known and have been used for control in some applications. In U.S. Pat. No. 4,149,716, a head band with electrodes is used to generate signals for wired control of visual displays in a television display game. In U.S. Pat. No. 5,482,051, electromyographic sensors are placed on the back of a user's hand to provide for the realistic "squeezing of objects" in a virtual reality application. U.S. Pat. No. 5,252,102 discloses orthotic and prosthetic devices which are controlled with myoswitches in connection with wireless communication. As described in U.S. Pat. No. 5,679,004, a body suit has myoelectric sensors for contact with an arm, where the signals therefrom are broadcasted to a remote station for comparison of teacher and student motions. U.S. Pat. No. 5,692,417 describes the combined use of EEG and EMG signals to produce control signals for electronic musical instruments and video games. None of these patents describes a wireless myoelectric apparatus for operative control of a portable electronic device with a relatively large number of clearly discernible human commands.
Accordingly, there is an existing need to provide a convenient and easy-to-use user interface for small portable electronic devices.